A Principal Component Analysis scatterplot of bioacoustics variables of Otus species and B the correlation circle in which ‘contrib’ corresponds to the contribution of the variables in accounting for the variability in the Principal components. Bioacoustic parameters – F1: frequency at start; F2: frequency at end; F3: frequency at 25% of total duration; F4: frequency at midpoint; F5: frequency at 75% of total duration; F6: frequency at maximum amplitude; F7: maximum frequency; F8: minimum frequency; DT1: total duration; DT2: time to maximum amplitude; DT3: time to maximum frequency; DT4: internote interval; DF1: frequency drop from start to end; DF2: frequency range; DFT1: slope from 25% to 75% of total duration; DFT2: slope from midpoint to end.

  Part of: Melo M, Freitas B, Verbelen P, da Costa SR, Pereira H, Fuchs J, Sangster G, Correia MN, de Lima RF, Crottini A (2022) A new species of scops-owl (Aves, Strigiformes, Strigidae, Otus) from Príncipe Island (Gulf of Guinea, Africa) and novel insights into the systematic affinities within Otus. ZooKeys 1126: 1-54. https://doi.org/10.3897/zookeys.1126.87635